scholarly journals Sol-Gel Synthesis, Structure, Morphology and Magnetic Properties of Ni0.6Mn0.4Fe2O4 Nanoparticles Embedded in SiO2 Matrix

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3455
Author(s):  
Thomas Dippong ◽  
Erika Andrea Levei ◽  
Iosif Grigore Deac ◽  
Ioan Petean ◽  
Gheorghe Borodi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Secondary Phase ◽  
Ferromagnetic Behavior ◽  
Sio2 Matrix ◽  
Calcination Temperatures ◽  
Structure Morphology ◽  
A Minor ◽  
Sol Gel Synthesis

The structure, morphology and magnetic properties of (Ni0.6Mn0.4Fe2O4)α(SiO2)100−α (α = 0–100%) nanocomposites (NCs) produced by sol-gel synthesis were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and vibrating sample magnetometry (VSM). At low calcination temperatures (300 °C), poorly crystallized Ni0.6Mn0.4Fe2O4, while at high calcination temperatures, well-crystallized Ni0.6Mn0.4Fe2O4 was obtained along with α-Fe2O3, quartz, cristobalite or iron silicate secondary phase, depending on the Ni0.6Mn0.4Fe2O4 content in the NCs. The average crystallite size increases from 2.6 to 74.5 nm with the increase of calcination temperature and ferrite content embedded in the SiO2 matrix. The saturation magnetization (Ms) enhances from 2.5 to 80.5 emu/g, the remanent magnetization (MR) from 0.68 to 12.6 emu/g and the coercive field (HC) from 126 to 260 Oe with increasing of Ni0.6Mn0.4Fe2O4 content in the NCs. The SiO2 matrix has a diamagnetic behavior with a minor ferromagnetic fraction, Ni0.6Mn0.4Fe2O4 embedded in SiO2 matrix displays superparamagnetic behavior, while unembedded Ni0.6Mn0.4Fe2O4 has a high-quality ferromagnetic behavior.

Microstructure and Magnetic Properties of La-Doped Barium-Ferrite

2013 ◽  
Vol 668 ◽  
pp. 706-709
Author(s):  
Chang Sen Zhang ◽  
Leia Yang
Keyword(s):  
Magnetic Properties ◽  
Quantum Interference ◽  
Barium Ferrite ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Structure Morphology ◽  
Barium Ferrites ◽  
La Doped

The La-doped barium ferrites microparticles were successful synthesized by citrate sol-gel method. The structure, morphology and magnetic properties of the ferrite were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), differential thermal analysis (TG-DSC) and superconducting quantum interference device (SQUID). The results showed that the average crystallite size of La-doped barium-ferrite decreased with increasing La content. The morphology of the barium ferrite was spherical particles; however, doped lanthanum, barium ferrite changed into laminated structure. In addition, doping lanthanum improved the magnetic properties of the ferrite. The saturation magnetization (Ms) of La-doped M-type barium ferrite 67.70emu/g, it was greater than the non-doped M-type barium ferrite 57.45emu/g.

scholarly journals Low temperature superparamagnetic nanocomposites obtained by Fe(acac)3-SiO2-PVA hybrid xerogel thermolysis

2016 ◽  
Vol 10 (4) ◽  
pp. 265-275 ◽  
Author(s):  
Catalin Ianasi ◽  
Otilia Costisor ◽  
Ana-Maria Putz ◽  
Radu Lazau ◽  
Adina Negrea ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Spinel Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Weight Percent ◽  
Silica Xerogel ◽  
Nominal Composition ◽  
One Pot ◽  
Calcination Temperatures ◽  
Sol Gel Synthesis

Fe(acac)3/silica/PVA hybrid xerogel nanocomposite was obtained by one pot acid catalysed sol-gel synthesis using the homogeneous mixture of iron(III) acetylacetonate (Fe(acac)3), tetraethylorthosilicate (TEOS), and polyvinyl alcohol (PVA). Nominal composition ratio of iron oxide/silica was 15/85 (weight percent). Nitric acid was used as catalyst. Another sample of Fe(acac)3/silica xerogel without PVA addition was prepared in the similar processing conditions. Based on thermal analysis studies, the thermal behaviour of both xerogel samples was unveiled and it allowed choosing the optimal calcination temperatures in order to obtain iron oxide silica magnetic nanocomposite samples. The two xerogel (with and without PVA) samples were thermally treated, in air, at 220, 260 and 300?C and characterized by different techniques. XRD investigations revealed phase composition evolution with calcination temperature, from cubic spinel phase (maghemite) to hexagonal stable hematite containing nanocomposite of 10-20 nm average crystallite size. These findings were confirmed by M?ssbauer spectroscopy. Up to 300?C, the surface area and total pores volume increased with temperature for all samples. By calcination at the same temperature, the hybrid xerogel containing PVA resulted in significantly higher magnetization and free volume values in comparison with the sample without PVA.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

scholarly journals Enhanced Magnetic Properties of BiFeO3 Thin Films by Doping: Analysis of Structure and Morphology

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 711 ◽  
Author(s):  
Yilin Zhang ◽  
Yuhan Wang ◽  
Ji Qi ◽  
Yu Tian ◽  
Mingjie Sun ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Sol Gel ◽  
Exchange Interactions ◽  
Ferromagnetic Behavior ◽  
Ferromagnetic Properties ◽  
Structure And Morphology ◽  
Related Diversification ◽  
Lattice Distortions ◽  
Mn Doped

The improvement of ferromagnetic properties is critical for the practical application of multiferroic materials, to be exact, BiFeO3 (BFO). Herein, we have investigated the evolution in the structure and morphology of Ho or/and Mn-doped thin films and the related diversification in ferromagnetic behavior. BFO, Bi0.95Ho0.05FeO3 (BHFO), BiFe0.95Mn0.05O3 (BFMO) and Bi0.95Ho0.05Fe0.95Mn0.05O3 (BHFMO) thin films are synthesized via the conventional sol-gel method. Density, size and phase structure are crucial to optimize the ferromagnetic properties. Specifically, under the applied magnetic field of 10 kOe, BHFO and BFMO thin films can produce obvious magnetic properties during magnetization and, additionally, doping with Ho and Mn (BHFMO) can achieve better magnetic properties. This enhancement is attributed to the lattice distortions caused by the ionic sizes difference between the doping agent and the host, the generation of the new exchange interactions and the inhibition of the antiferromagnetic spiral modulated spin structure. This study provides key insights of understanding the tunable ferromagnetic properties of co-doped BFO.

Enhanced soft magnetic properties of iron powders through coating MnZn ferrite by one-step sol–gel synthesis

2019 ◽  
Vol 28 (5) ◽  
pp. 057503 ◽  
Author(s):  
Dong Liu ◽  
Shanmin Gao ◽  
Rencheng Jin ◽  
Feng Wang ◽  
Xiaoxiao Chu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Mnzn Ferrite ◽  
Iron Powders ◽  
One Step ◽  
Sol Gel Synthesis

Sucrose as a sol-gel synthesis additive for tuning spinel inversion and improving the magnetic properties of CoFe2O4 nanoparticles

2020 ◽  
Vol 46 (8) ◽  
pp. 12759-12766
Author(s):  
Camila Stockey Erhardt ◽  
Luis Eduardo Caldeira ◽  
Janio Venturini ◽  
Saulo Roca Bragança ◽  
Carlos Pérez Bergmann
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Cofe2o4 Nanoparticles ◽  
Sol Gel Synthesis

scholarly journals Preparation of Bi-substituted YIG garnets by sol-gel synthesis and their magnetic properties.

1990 ◽  
Vol 14 (2) ◽  
pp. 247-250 ◽  
Author(s):  
K. Matsumoto ◽  
K. Yamaguchi ◽  
A. Ueno ◽  
T. Fujii
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Sol Gel Synthesis

Magnetic Properties of the La0.50Ba0.50MnO3 Nanomanganites

2009 ◽  
Vol 152-153 ◽  
pp. 135-138 ◽  
Author(s):  
S.V. Trukhanov ◽  
A.V. Trukhanov ◽  
Christian E. Botez ◽  
H. Szymczak
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Sol Gel ◽  
Exchange Interactions ◽  
Average Crystallite Size ◽  
Anomalous Behavior ◽  
Air Atmosphere ◽  
Crystallite Surface ◽  
Step Heat Treatment ◽  
Lattice Compression

Nanocrystalline La0.50Ba0.50MnO3 manganite was synthesized by an optimized sol-gel method. The initial sample was subjected to step-by-step heat treatment under air atmosphere. The ion stoichiometry, the morphology of crystallites of ceramics, and the magnetic properties were studied. It is established that the average crystallite size increases with increasing annealing temperature. All of the samples studied are characterized by a perovskite-like cubic structure, with the unit cell parameter a increasing continuously with the average crystallite size. The most significant lattice compression occurs in the sample with an average crystallite size of ~ 30 nm. The increase in the average crystallite size causes a nonmonotonic increase in the Curie temperature and in the spontaneous magnetic moment. The anomalous behavior of the magnetic properties of the La0.50Ba0.50MnO3 manganites obtained is explained by the competition between two size effects, namely, the frustration of the indirect exchange interactions Mn3+ – O – Mn4+ on the nanocrystallite surface and the crystal lattice compression due to the crystallite surface tension.

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